US20030179718A1 - Route selection in a communications network using combined values of metrics of different characteristics - Google Patents
Route selection in a communications network using combined values of metrics of different characteristics Download PDFInfo
- Publication number
- US20030179718A1 US20030179718A1 US10/392,174 US39217403A US2003179718A1 US 20030179718 A1 US20030179718 A1 US 20030179718A1 US 39217403 A US39217403 A US 39217403A US 2003179718 A1 US2003179718 A1 US 2003179718A1
- Authority
- US
- United States
- Prior art keywords
- metric
- metrics
- combined
- nodes
- node
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W40/00—Communication routing or communication path finding
- H04W40/02—Communication route or path selection, e.g. power-based or shortest path routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/12—Shortest path evaluation
- H04L45/122—Shortest path evaluation by minimising distances, e.g. by selecting a route with minimum of number of hops
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/12—Shortest path evaluation
- H04L45/124—Shortest path evaluation using a combination of metrics
Definitions
- the present invention relates to a method for selecting routes in a communications network.
- This invention is particularly suitable for selecting routes in a wireless network formed by a plurality of wireless nodes.
- each cell-sites functions as a source/destination node for a mobile terminal or a transit node for repeating packets between neighbor cell-sites. Since communication within the access network is predominantly a flow of packets to and from the core network packets from the access network follow the pattern of a tree, with a node on the core network serving as a root of the tree topology.
- distance vector routing is suitable for a tree topology. Further, distance vector routing is preferred over link state routing because the former requires less routing information than the latter.
- a tree topology wireless network is built up by initially broadcasting a control packet from a core (root) node, containing its node identifier in its source address field and a metric field which is set to zero. An access node that receives it reads the source node identifier and updates the metric value by adding to it the cost of the route on its upstream side to the source node.
- the access node If the hop count number is used as a measure of the route cost the metric is updated by adding the hop count “1” to the received metric value. If the transmission loss is used as a measure of the route cost, the access node calculates the transmission loss of the received RF signal from its field strength and sums the calculated value to the received metric value. The access node then stores the updated metric in its memory. Initially, there is only one metric value that is stored in the memory. Hence the source node is recognized as an upstream node. Then, the access node broadcasts a control packet containing the updated metric, with its source and destination address fields being set with its own identifier and the identifier of the upstream node, respectively. As the same process is repeated on neighbor access nodes, a sufficient amount of metric data is stored in their memory to select a least-cost route to the core node.
- a wireless network configured in his way is characteristic of the metric used. If the hop count is used as a metric value, the network will be comprised of least-hop-count routes. If the transmission loss or signal-to-interference-noise ratio is used, the network will ensure high quality transmission. On the other hand, the use of hop counts will result in a network where the nodes are spaced at long distance apart. Hence, signals suffer distortion and interference. Further, the use of transmission loss and SINR as a metric will result in a network dominated by high number hop-count routes where signals experience long processing delays. Thus, the characteristic of a resulting network not only has the advantage of the metric used but also has its disadvantage.
- Another object of the present invention is to perform route selection for a network node by selecting a route to an upstream node of a tree topology having a minimum value of combined metrics.
- a still further object of the present invention is to perform route selection for a wireless node by assigning a limited number of wireless links to high efficient routes to downstream nodes of a tree topology.
- a method of determining a route in a communications network comprises the steps of transmitting control packets from a plurality of nodes via a plurality of routes to a local node and receiving, at the local node, control packets from a plurality of nodes.
- Each of the control packets contains first and second metric values of different transmission characteristics of a route on which the control packet is transmitted.
- the first and second metric values of each of the received control packets are combined together to produce a plurality of combined metrics and at least one of the routes is selected according to the combined metrics.
- the route selection is performed by detecting a minimum value of the combined metrics and selecting at least one of the routes having the detected minimum value.
- the combined metric is obtained by weighting the second metric and summing the weighted second metric with the first metric.
- the first and second metrics of each control packet may be updated and a minimum value of combined metrics is detected and a route having the minimum combined metric value is selected as the route to a core node.
- control packets are arriving from downstream nodes, a plurality of smaller values of the combined metrics are detected in ascending order of their combined value corresponding in number to wireless links that can be established from the local node and routes of the detected smaller values are selected.
- the present invention provides a method of determining a route in a wireless communications network, comprising the steps of (a) broadcasting control packets from a plurality of wireless nodes via a plurality of routes to a local wireless node, each of the control packets containing first and second metric values of different transmission characteristics of a corresponding one of the routes, (b) receiving, at the local node, control packets from the plurality of nodes, (c) determining whether the received control packets are received from upstream nodes or downstream nodes, (d) if the packets are received from upstream nodes, updating the first and second metrics of the received control packets and combining the first and second metrics of the received control packets to produce a plurality of combined metrics and selecting one of the routes according to the plurality of combined metrics, and (e) if the packets are received from downstream nodes, combining the first and second metrics of the received control packets to produce a plurality of combined metrics and determining smaller values of the combined metrics in
- the present invention provides a network node for a communications network wherein the network node is one of a plurality of interconnected nodes of the network.
- the network node comprises an interface connected to the network, a metric table having a plurality of entries, and a routing control module.
- the routing control module broadcasts a control packet to the network via the interface, containing first and second metric values of different transmission characteristics of the route, receives control packets from a plurality of nodes via the interface.
- the first and second metric values of the received control packets are stored in respective entries of the metric table, and the first and second metric values of each table entry are combined together to produce a plurality of combined metrics and at least one of the routes is selected according to the combined metrics.
- FIG. 1 is a block diagram of a communications network of the present invention illustrating a wireline core network and a number of wireless access networks connected to the core network;
- FIG. 2 is a block diagram of a wireless access node of FIG. 1 according to a first embodiment of the present invention
- FIG. 3 is an illustration of the data format of a control packet of the present invention.
- FIG. 4 is a flowchart of the operation of the wireless access node of the first embodiment of the present invention.
- FIG. 5 is a flowchart of an alternative form of route selection subroutine of FIG. 4;
- FIG. 6 is an illustration of a conversion table
- FIG. 7 is a block diagram of a wireless access node of FIG. 1 according to a second embodiment of the present invention.
- FIG. 8 is a flowchart of the operation of the wireless access node of the second embodiment of the present invention.
- the network comprises a wireline core network 10 and a plurality of wireless access networks 11 , 12 , 13 connected to the core network 10 via respective wireline links 14 such as optical links.
- Each wireless access network is formed by a wireless core node and a plurality of wireless access nodes of the present invention.
- the node A is the core node and is connected to the core network 10 via the optical link 14 and the nodes B through G are the access nodes.
- wireless links are established between the core node and the access nodes depending on their locations and usable directional antennas.
- the core node A has one of its antennas beamed to the access node B to which access nodes E and G are wirelessly connected in tandem.
- Core node A has its other antenna beamed to the access node C to which access nodes D and F are wirelessly connected in tandem.
- the core node A functions as a root node of a tree topology in which the access nodes B through G are connected. For each access node, there is an upstream node on its near side to the core node A and a downstream node on its far side from the core node.
- the wireless access node of a first embodiment of this invention is shown in FIG. 2.
- the access node is comprised of a wireless interface 21 for operating with one or more directional antennas 20 to establish wireless links with neighbor nodes.
- a routing control module 22 is connected to the wireless interface 21 for broadcasting and receiving control packets to and from the neighbor nodes.
- the control packet has a housekeeping field 31 for setting data necessary for exchanging the control packet, a source address field 32 for setting a source node identifier, a first metric field 33 for setting a first metric value, a second metric field 34 for setting a second metric value, and a destination address field 35 for setting a destination node identifier.
- Routing control module 22 is associated with an upstream metric table 23 .
- Metric table 23 has a plurality of entries for source nodes located on the upstream side of the local access node. Each entry is used for setting a source node identifier in a source ID field 24 , updated values of first and second metrics in updated metrics fields 25 , 26 and a combined metric value in a combined metric field 27 .
- the routing control module 22 operates by storing data into a vacant entry of the metric table 23 in response to receipt of a control packet from a neighbor node and selecting a route to an upstream node when sufficient data are stored in the metric table 23 .
- the operation of the routing control module 22 begins with step 41 when a control packet is received from the network.
- the routing control module reads the destination node ID, and determines whether the destination node ID is equal to the node ID of the local node. If this is the case, the local node is targeted by the source node as an upstream node. Hence, the routing control module terminates the routine, recognizing that the source node is no longer a candidate upstream node of the local node.
- the routing control module determines that the source node can possibly be a candidate upstream node of the local node and proceeds to step 44 to read the source node ID and the first and second metrics from the packet and update the first and second metric values individually.
- Metrics that can be employed include hop count number, transmission loss and reciprocal of SINR. Assume that the first metric is the transmission loss and the second metric is the hop count number. If the first and second metrics of the control packet are 35.0 dB and 2 hops, respectively, and the transmission loss of the route from the source node to the local node is 30.0 dB, then the first and second metric values are updated to 36.2 dB and 3 hops, respectively.
- the routing control module stores the source node ID and the updated values of the first and second metrics into a vacant entry of the upstream metric table 23 .
- Route selection subroutine 46 is then performed, which begins with decision step 47 to determine whether sufficient data are stored in the upstream metric table 23 to make a determination on a route to a core node. The determination may be based on the time lapse from the instant a first control packet is received or the number of control packets received from a candidate upstream node.
- step 47 If the decision at step 47 is affirmative, flow proceeds to step 48 to read the first and second metric values from the first entry of the upstream metric table 23 and calculate a combined metric for the upstream source node according to the following equation:
- the combined metric value of the upstream node is then stored in the combined metric field 27 of the current entry from which the two metric values have been retrieved. Steps 48 and 49 are repeated by successively shifting the read address point from one entry to the next until combined metric values are calculated for all source node identifiers (step 50 ). When the decision at step 50 is affirmative, flow proceeds to step 51 to read all data stored in the combined metric field 27 of the upstream metric table. From the combined metric data, the routing control module 22 selects a minimum combined metric value as the route to a core (root) node.
- the calculation yields a combined metric value of 43.0 dB. If there is a route B whose first metric is 42.0 dB and the second metric is one hop, the combined metric is 42.0 dB. Since the route B has a smaller value of combined metric than the combined metric value of route A, the route B will be selected at step 51 .
- the second metric and the coefficient are multiplied on the logarithmic scale and the multiplied value is summed with the first metric on the normal scale. If the second metric and the coefficient are multiplied on the normal scale and the multiplied value is summed with the first metric on the logarithmic scale, the combined metric value equals 63.0 dB.
- route selection subroutine 46 may alternatively begin with calculation step 61 to produce a combined metric, which is stored in the upstream metric table (step 62 ). Metric table 23 is then checked at step 63 to see if sufficient data has been stored to make a route selection. If this is the case, step 64 is executed to select a minimum combined metric as a route to the core node.
- the coefficient ⁇ may be varied with hop count numbers as indicated in a conversion table 65 shown in FIG. 6.
- the coefficient ⁇ is 10 dB for hop counts of 1 and 2 and jumps to infinity when the hop count is 3.
- the coefficient ⁇ is 10 dB for hop counts of 1 and 2 and jumps to infinity when the hop count is 3.
- the route C has a smaller combined metric value than that of the route A (i.e., 40.0 dB), the former is selected as a route to the core node. If the route C has a hop count equal to 3, the coefficient ⁇ is of infinite value and the route A is selected.
- the use of such a variable coefficient is beneficial for applications where network performance degrades seriously when the second metric (i.e., hop count number) exceeds some critical value.
- the number of downstream nodes located within the transmission range of a local node is greater than the number of wireless links that can be established, it is necessary to use some decision algorithm to limit the number of nodes that can be selected as downstream nodes to the number of such wireless links (i.e., the number of usable antennas). If a local node has three wireless links that can be established with its antennas, for example, one of the links is use for an upstream node, leaving only two links for downstream nodes.
- a second embodiment of the present invention illustrated in FIG. 7, illustrates a decision algorithm of the routing control module 23 for selecting downstream nodes.
- the second embodiment differs from the previous embodiment by the inclusion of a downstream metric table 70 identical to the upstream metric table 23 .
- the routing control module determines that the source node may possibly be a downstream node of the local node. In this case, the routing control module proceeds from step 43 to step 81 to store the source node ID and the two metric values of the received control packet into a vacant entry of the downstream metric table 70 . If not sufficient data is stored in the metric table 70 , the routine is terminated (step 82 ). Otherwise, flow proceeds from step 82 to step 83 to read the first and second metric values from the first entry of the downstream metric table 70 and calculate a combined values of these two metric values in the same manner as described above.
- step 84 The calculated combined metric is then stored in the current entry of the downstream metric table from which the metric values have been retried (step 84 ). Steps 83 and 84 are repeated by successively shifting the read address point from one entry to the next until combined metric values are calculated for all source node identifiers of table 70 (step 85 ). When the decision at step 85 is affirmative, flow proceeds to step 86 to read all data stored in the combined metric field of the downstream metric table 70 . Smaller combined metric values are selected from the read data corresponding in number to usable antennas of the local node as routes to downstream nodes.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
Description
- 1. Field of the Invention
- The present invention relates to a method for selecting routes in a communications network. This invention is particularly suitable for selecting routes in a wireless network formed by a plurality of wireless nodes.
- 2. Description of the Related Art
- In a communications network where a wireless cell-sites are interconnected by wireless links (i.e., radio beams) to form a wireless access network and the latter is connected to a wireline core network via optical links, each cell-sites functions as a source/destination node for a mobile terminal or a transit node for repeating packets between neighbor cell-sites. Since communication within the access network is predominantly a flow of packets to and from the core network packets from the access network follow the pattern of a tree, with a node on the core network serving as a root of the tree topology.
- Two routing algorithms are available. One is the distance vector routing algorithm, the other being the link state routing algorithm. It is known that distance vector routing is suitable for a tree topology. Further, distance vector routing is preferred over link state routing because the former requires less routing information than the latter. In distance vector routing, a tree topology wireless network is built up by initially broadcasting a control packet from a core (root) node, containing its node identifier in its source address field and a metric field which is set to zero. An access node that receives it reads the source node identifier and updates the metric value by adding to it the cost of the route on its upstream side to the source node. If the hop count number is used as a measure of the route cost the metric is updated by adding the hop count “1” to the received metric value. If the transmission loss is used as a measure of the route cost, the access node calculates the transmission loss of the received RF signal from its field strength and sums the calculated value to the received metric value. The access node then stores the updated metric in its memory. Initially, there is only one metric value that is stored in the memory. Hence the source node is recognized as an upstream node. Then, the access node broadcasts a control packet containing the updated metric, with its source and destination address fields being set with its own identifier and the identifier of the upstream node, respectively. As the same process is repeated on neighbor access nodes, a sufficient amount of metric data is stored in their memory to select a least-cost route to the core node.
- A wireless network configured in his way is characteristic of the metric used. If the hop count is used as a metric value, the network will be comprised of least-hop-count routes. If the transmission loss or signal-to-interference-noise ratio is used, the network will ensure high quality transmission. On the other hand, the use of hop counts will result in a network where the nodes are spaced at long distance apart. Hence, signals suffer distortion and interference. Further, the use of transmission loss and SINR as a metric will result in a network dominated by high number hop-count routes where signals experience long processing delays. Thus, the characteristic of a resulting network not only has the advantage of the metric used but also has its disadvantage.
- It is therefore an object of the present invention to perform route selection for a network node for increasing the advantageous side of metrics by combining their metric values.
- Another object of the present invention is to perform route selection for a network node by selecting a route to an upstream node of a tree topology having a minimum value of combined metrics.
- A still further object of the present invention is to perform route selection for a wireless node by assigning a limited number of wireless links to high efficient routes to downstream nodes of a tree topology.
- According to a first aspect of the present invention, there is provided a method of determining a route in a communications network. The method comprises the steps of transmitting control packets from a plurality of nodes via a plurality of routes to a local node and receiving, at the local node, control packets from a plurality of nodes. Each of the control packets contains first and second metric values of different transmission characteristics of a route on which the control packet is transmitted. At the local node, the first and second metric values of each of the received control packets are combined together to produce a plurality of combined metrics and at least one of the routes is selected according to the combined metrics.
- The route selection is performed by detecting a minimum value of the combined metrics and selecting at least one of the routes having the detected minimum value. The combined metric is obtained by weighting the second metric and summing the weighted second metric with the first metric.
- If the control packets are arriving from upstream nodes, the first and second metrics of each control packet may be updated and a minimum value of combined metrics is detected and a route having the minimum combined metric value is selected as the route to a core node.
- If the control packets are arriving from downstream nodes, a plurality of smaller values of the combined metrics are detected in ascending order of their combined value corresponding in number to wireless links that can be established from the local node and routes of the detected smaller values are selected.
- According to a further aspect, the present invention provides a method of determining a route in a wireless communications network, comprising the steps of (a) broadcasting control packets from a plurality of wireless nodes via a plurality of routes to a local wireless node, each of the control packets containing first and second metric values of different transmission characteristics of a corresponding one of the routes, (b) receiving, at the local node, control packets from the plurality of nodes, (c) determining whether the received control packets are received from upstream nodes or downstream nodes, (d) if the packets are received from upstream nodes, updating the first and second metrics of the received control packets and combining the first and second metrics of the received control packets to produce a plurality of combined metrics and selecting one of the routes according to the plurality of combined metrics, and (e) if the packets are received from downstream nodes, combining the first and second metrics of the received control packets to produce a plurality of combined metrics and determining smaller values of the combined metrics in ascending order of combined metrics corresponding in number to wireless links that can be established from the local wireless node and selecting routes having the detected smaller values from the plurality of routes.
- According to a still further aspect, the present invention provides a network node for a communications network wherein the network node is one of a plurality of interconnected nodes of the network. The network node comprises an interface connected to the network, a metric table having a plurality of entries, and a routing control module. The routing control module broadcasts a control packet to the network via the interface, containing first and second metric values of different transmission characteristics of the route, receives control packets from a plurality of nodes via the interface. In the routing control module, the first and second metric values of the received control packets are stored in respective entries of the metric table, and the first and second metric values of each table entry are combined together to produce a plurality of combined metrics and at least one of the routes is selected according to the combined metrics.
- The present invention will be described in detail further with reference to the following drawings, in which:
- FIG. 1 is a block diagram of a communications network of the present invention illustrating a wireline core network and a number of wireless access networks connected to the core network;
- FIG. 2 is a block diagram of a wireless access node of FIG. 1 according to a first embodiment of the present invention;
- FIG. 3 is an illustration of the data format of a control packet of the present invention;
- FIG. 4 is a flowchart of the operation of the wireless access node of the first embodiment of the present invention;
- FIG. 5 is a flowchart of an alternative form of route selection subroutine of FIG. 4;
- FIG. 6 is an illustration of a conversion table;
- FIG. 7 is a block diagram of a wireless access node of FIG. 1 according to a second embodiment of the present invention; and
- FIG. 8 is a flowchart of the operation of the wireless access node of the second embodiment of the present invention.
- Referring now to FIG. 1, there is shown a communications network. The network comprises a
wireline core network 10 and a plurality ofwireless access networks core network 10 viarespective wireline links 14 such as optical links. Each wireless access network is formed by a wireless core node and a plurality of wireless access nodes of the present invention. In the case ofaccess network 10, the node A is the core node and is connected to thecore network 10 via theoptical link 14 and the nodes B through G are the access nodes. Within each access node, wireless links are established between the core node and the access nodes depending on their locations and usable directional antennas. In the illustrated example, the core node A has one of its antennas beamed to the access node B to which access nodes E and G are wirelessly connected in tandem. Core node A has its other antenna beamed to the access node C to which access nodes D and F are wirelessly connected in tandem. - Therefore, the core node A functions as a root node of a tree topology in which the access nodes B through G are connected. For each access node, there is an upstream node on its near side to the core node A and a downstream node on its far side from the core node.
- The wireless access node of a first embodiment of this invention is shown in FIG. 2. The access node is comprised of a
wireless interface 21 for operating with one or moredirectional antennas 20 to establish wireless links with neighbor nodes. Arouting control module 22 is connected to thewireless interface 21 for broadcasting and receiving control packets to and from the neighbor nodes. - As shown in FIG. 3, the control packet has a
housekeeping field 31 for setting data necessary for exchanging the control packet, asource address field 32 for setting a source node identifier, a firstmetric field 33 for setting a first metric value, a secondmetric field 34 for setting a second metric value, and adestination address field 35 for setting a destination node identifier. -
Routing control module 22 is associated with an upstream metric table 23. Metric table 23 has a plurality of entries for source nodes located on the upstream side of the local access node. Each entry is used for setting a source node identifier in a source ID field 24, updated values of first and second metrics in updated metrics fields 25, 26 and a combined metric value in a combinedmetric field 27. - According to the flowchart of FIG. 4, the
routing control module 22 operates by storing data into a vacant entry of the metric table 23 in response to receipt of a control packet from a neighbor node and selecting a route to an upstream node when sufficient data are stored in the metric table 23. - In FIG. 4, the operation of the
routing control module 22 begins withstep 41 when a control packet is received from the network. Atstep 42, the routing control module reads the destination node ID, and determines whether the destination node ID is equal to the node ID of the local node. If this is the case, the local node is targeted by the source node as an upstream node. Hence, the routing control module terminates the routine, recognizing that the source node is no longer a candidate upstream node of the local node. - If the decision at
step 43 is negative, the routing control module determines that the source node can possibly be a candidate upstream node of the local node and proceeds to step 44 to read the source node ID and the first and second metrics from the packet and update the first and second metric values individually. Metrics that can be employed include hop count number, transmission loss and reciprocal of SINR. Assume that the first metric is the transmission loss and the second metric is the hop count number. If the first and second metrics of the control packet are 35.0 dB and 2 hops, respectively, and the transmission loss of the route from the source node to the local node is 30.0 dB, then the first and second metric values are updated to 36.2 dB and 3 hops, respectively. Atstep 45, the routing control module stores the source node ID and the updated values of the first and second metrics into a vacant entry of the upstream metric table 23. -
Route selection subroutine 46 is then performed, which begins withdecision step 47 to determine whether sufficient data are stored in the upstream metric table 23 to make a determination on a route to a core node. The determination may be based on the time lapse from the instant a first control packet is received or the number of control packets received from a candidate upstream node. - If the decision at
step 47 is affirmative, flow proceeds to step 48 to read the first and second metric values from the first entry of the upstream metric table 23 and calculate a combined metric for the upstream source node according to the following equation: - Combined metric=first metric+second metric×α
- where α is a coefficient.
- The combined metric value of the upstream node is then stored in the combined
metric field 27 of the current entry from which the two metric values have been retrieved.Steps 48 and 49 are repeated by successively shifting the read address point from one entry to the next until combined metric values are calculated for all source node identifiers (step 50). When the decision atstep 50 is affirmative, flow proceeds to step 51 to read all data stored in the combinedmetric field 27 of the upstream metric table. From the combined metric data, therouting control module 22 selects a minimum combined metric value as the route to a core (root) node. - If the first metric of a route A is 40.0 dB, the second metric of the route is 2 hops and the coefficient α is equal to 20.0 dB, the calculation yields a combined metric value of 43.0 dB. If there is a route B whose first metric is 42.0 dB and the second metric is one hop, the combined metric is 42.0 dB. Since the route B has a smaller value of combined metric than the combined metric value of route A, the route B will be selected at
step 51. - In the above example, the second metric and the coefficient are multiplied on the logarithmic scale and the multiplied value is summed with the first metric on the normal scale. If the second metric and the coefficient are multiplied on the normal scale and the multiplied value is summed with the first metric on the logarithmic scale, the combined metric value equals 63.0 dB.
- By combining different metric values as a measure of route selection, the advantageous characteristics of both metrics are integrated in a single network.
- As shown in FIG. 5,
route selection subroutine 46 may alternatively begin withcalculation step 61 to produce a combined metric, which is stored in the upstream metric table (step 62). Metric table 23 is then checked atstep 63 to see if sufficient data has been stored to make a route selection. If this is the case, step 64 is executed to select a minimum combined metric as a route to the core node. - The coefficient α may be varied with hop count numbers as indicated in a conversion table65 shown in FIG. 6. In an example, the coefficient α is 10 dB for hop counts of 1 and 2 and jumps to infinity when the hop count is 3. Consider a route C where the coefficient α is 10 dB for a hop count smaller than 3, and the combined metric is calculated as being equal to 36.2 dB. In this case, the route C has a smaller combined metric value than that of the route A (i.e., 40.0 dB), the former is selected as a route to the core node. If the route C has a hop count equal to 3, the coefficient α is of infinite value and the route A is selected. The use of such a variable coefficient is beneficial for applications where network performance degrades seriously when the second metric (i.e., hop count number) exceeds some critical value.
- If the number of downstream nodes located within the transmission range of a local node is greater than the number of wireless links that can be established, it is necessary to use some decision algorithm to limit the number of nodes that can be selected as downstream nodes to the number of such wireless links (i.e., the number of usable antennas). If a local node has three wireless links that can be established with its antennas, for example, one of the links is use for an upstream node, leaving only two links for downstream nodes.
- The use of combined metrics discussed above can be advantageously applied to the selection of downstream nodes. A second embodiment of the present invention, shown in FIG. 7, illustrates a decision algorithm of the
routing control module 23 for selecting downstream nodes. In FIG. 7, the second embodiment differs from the previous embodiment by the inclusion of a downstream metric table 70 identical to the upstream metric table 23. - The operation of the
routing control module 23 of FIG. 7 proceeds according to the flowchart of FIG. 8, in which parts corresponding to those of FIG. 4 are marked with the same numerals and the description thereof is omitted. - When the received destination node ID is equal to the identifier of the local node, the routing control module determines that the source node may possibly be a downstream node of the local node. In this case, the routing control module proceeds from
step 43 to step 81 to store the source node ID and the two metric values of the received control packet into a vacant entry of the downstream metric table 70. If not sufficient data is stored in the metric table 70, the routine is terminated (step 82). Otherwise, flow proceeds fromstep 82 to step 83 to read the first and second metric values from the first entry of the downstream metric table 70 and calculate a combined values of these two metric values in the same manner as described above. - The calculated combined metric is then stored in the current entry of the downstream metric table from which the metric values have been retried (step84).
Steps 83 and 84 are repeated by successively shifting the read address point from one entry to the next until combined metric values are calculated for all source node identifiers of table 70 (step 85). When the decision atstep 85 is affirmative, flow proceeds to step 86 to read all data stored in the combined metric field of the downstream metric table 70. Smaller combined metric values are selected from the read data corresponding in number to usable antennas of the local node as routes to downstream nodes. - It is seen that the use of combined metrics for selecting downstream nodes with a limited number of usable antennas allows higher efficient routes to be selected with priority over lower efficient routes.
Claims (28)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002077446A JP2003284114A (en) | 2002-03-20 | 2002-03-20 | Wireless transmission apparatus, path control method used therefor, and program thereof |
JP2002-077446 | 2002-03-20 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20030179718A1 true US20030179718A1 (en) | 2003-09-25 |
US8027275B2 US8027275B2 (en) | 2011-09-27 |
Family
ID=28035516
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/392,174 Expired - Fee Related US8027275B2 (en) | 2002-03-20 | 2003-03-20 | Route selection in a communications network using combined values of metrics of different characteristics |
Country Status (2)
Country | Link |
---|---|
US (1) | US8027275B2 (en) |
JP (1) | JP2003284114A (en) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030195005A1 (en) * | 2002-04-12 | 2003-10-16 | Nec Corporation | Radio transmission apparatus, routing method, and routing program of radio network |
US20040220947A1 (en) * | 2003-05-02 | 2004-11-04 | International Business Machines Corporation | Method and apparatus for real-time intelligent workload reporting in a heterogeneous environment |
US20040252643A1 (en) * | 2003-06-05 | 2004-12-16 | Meshnetworks, Inc. | System and method to improve the network performance of a wireless communications network by finding an optimal route between a source and a destination |
US20050041591A1 (en) * | 2003-08-22 | 2005-02-24 | Samsung Electronics Co., Ltd. | Apparatus and method for determining aggregated link costs in a mobile ad hoc network |
US20060104205A1 (en) * | 2004-11-12 | 2006-05-18 | Meshnetworks, Inc. | System and method to scout for routes in a wireless network |
US20070066234A1 (en) * | 2003-07-03 | 2007-03-22 | Rotani, Inc. | Method and apparatus for high throughput multiple radio sectorized wireless cell |
US20070127379A1 (en) * | 2005-12-07 | 2007-06-07 | Hrishikesh Gossain | Method and system for improving a wireless communication route |
US20080205360A1 (en) * | 2007-02-27 | 2008-08-28 | Tropos Networks, Inc. | Balancing clusters of a wireless mesh network |
US20090168653A1 (en) * | 2007-12-31 | 2009-07-02 | St Pierre Robert P | Method and Apparatus for Mesh Routing |
US20100082762A1 (en) * | 2008-09-29 | 2010-04-01 | Fujitsu Limited | Message tying processing method and apparatus |
US20110085461A1 (en) * | 2009-10-14 | 2011-04-14 | Ying Liu | Flexible network measurement |
US8199677B1 (en) * | 2005-12-14 | 2012-06-12 | Rockwell Collins, Inc. | Distance vector routing via multi-point relays |
US20210321241A1 (en) * | 2020-04-14 | 2021-10-14 | Soter Technologies, Llc | Systems and methods for notifying particular devices based on estimated distance |
US11233722B2 (en) * | 2017-12-12 | 2022-01-25 | Futurewei Technologies, Inc. | System and method for network topology management |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005168020A (en) | 2004-11-30 | 2005-06-23 | Nec Corp | Communication path control method and communication terminal for radio multi-hop network |
US20070147255A1 (en) * | 2005-12-23 | 2007-06-28 | Ozgur Oyman | Routing in wireless mesh networks |
WO2008106804A1 (en) * | 2007-03-07 | 2008-09-12 | Magna International Inc. | Vehicle interior classification system and method |
US10939353B2 (en) | 2016-08-02 | 2021-03-02 | Signify Holding B.V. | Reliable reporting in wireless mesh network |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6292832B1 (en) * | 1998-05-26 | 2001-09-18 | Cisco Technology, Inc. | System and method for determining a preferred service in a network |
US20020024935A1 (en) * | 2000-08-30 | 2002-02-28 | Nec Corporation | Radio network, relay node, core node, relay transmission method used in the same and program thereof |
US20030128687A1 (en) * | 2000-06-07 | 2003-07-10 | Worfolk Patrick A. | Multi-path dynamic routing algorithm |
US20030128710A1 (en) * | 1998-12-28 | 2003-07-10 | Fedyk Donald Wayne | Quasi-deterministic gateway selection algorithm for multi-domain source routed networks |
US6711159B1 (en) * | 1999-12-15 | 2004-03-23 | 3Com Corporation | Load balancing among media gateways |
US6795860B1 (en) * | 1999-04-05 | 2004-09-21 | Cisco Technology, Inc. | System and method for selecting a service with dynamically changing information |
US6856592B2 (en) * | 2001-03-15 | 2005-02-15 | Nortel Networks Limited | Method of providing restoration routes in a mesh network |
US7002917B1 (en) * | 1999-01-15 | 2006-02-21 | Cisco Technology, Inc. | Method for path selection in a network |
US7072304B2 (en) * | 2002-02-27 | 2006-07-04 | Nortel Networks Limited | Network path selection based on bandwidth |
US7158486B2 (en) * | 2001-03-12 | 2007-01-02 | Opcoast Llc | Method and system for fast computation of routes under multiple network states with communication continuation |
-
2002
- 2002-03-20 JP JP2002077446A patent/JP2003284114A/en active Pending
-
2003
- 2003-03-20 US US10/392,174 patent/US8027275B2/en not_active Expired - Fee Related
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6292832B1 (en) * | 1998-05-26 | 2001-09-18 | Cisco Technology, Inc. | System and method for determining a preferred service in a network |
US20030128710A1 (en) * | 1998-12-28 | 2003-07-10 | Fedyk Donald Wayne | Quasi-deterministic gateway selection algorithm for multi-domain source routed networks |
US7002917B1 (en) * | 1999-01-15 | 2006-02-21 | Cisco Technology, Inc. | Method for path selection in a network |
US6795860B1 (en) * | 1999-04-05 | 2004-09-21 | Cisco Technology, Inc. | System and method for selecting a service with dynamically changing information |
US6711159B1 (en) * | 1999-12-15 | 2004-03-23 | 3Com Corporation | Load balancing among media gateways |
US20030128687A1 (en) * | 2000-06-07 | 2003-07-10 | Worfolk Patrick A. | Multi-path dynamic routing algorithm |
US7233574B2 (en) * | 2000-06-07 | 2007-06-19 | Intel Corporation | Multi-path dynamic routing algorithm |
US20020024935A1 (en) * | 2000-08-30 | 2002-02-28 | Nec Corporation | Radio network, relay node, core node, relay transmission method used in the same and program thereof |
US7158486B2 (en) * | 2001-03-12 | 2007-01-02 | Opcoast Llc | Method and system for fast computation of routes under multiple network states with communication continuation |
US6856592B2 (en) * | 2001-03-15 | 2005-02-15 | Nortel Networks Limited | Method of providing restoration routes in a mesh network |
US7072304B2 (en) * | 2002-02-27 | 2006-07-04 | Nortel Networks Limited | Network path selection based on bandwidth |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7515911B2 (en) * | 2002-04-12 | 2009-04-07 | Nec Corporation | Radio transmission apparatus, routing method, and routing program of radio network |
US20030195005A1 (en) * | 2002-04-12 | 2003-10-16 | Nec Corporation | Radio transmission apparatus, routing method, and routing program of radio network |
US20040220947A1 (en) * | 2003-05-02 | 2004-11-04 | International Business Machines Corporation | Method and apparatus for real-time intelligent workload reporting in a heterogeneous environment |
US7280483B2 (en) * | 2003-06-05 | 2007-10-09 | Meshnetworks, Inc. | System and method to improve the network performance of a wireless communications network by finding an optimal route between a source and a destination |
US20040252643A1 (en) * | 2003-06-05 | 2004-12-16 | Meshnetworks, Inc. | System and method to improve the network performance of a wireless communications network by finding an optimal route between a source and a destination |
WO2004114690A1 (en) * | 2003-06-05 | 2004-12-29 | Meshnetworks, Inc. | Optimal routing in ad hac wireless communication network |
US20070066234A1 (en) * | 2003-07-03 | 2007-03-22 | Rotani, Inc. | Method and apparatus for high throughput multiple radio sectorized wireless cell |
US20050041591A1 (en) * | 2003-08-22 | 2005-02-24 | Samsung Electronics Co., Ltd. | Apparatus and method for determining aggregated link costs in a mobile ad hoc network |
US7480248B2 (en) * | 2003-08-22 | 2009-01-20 | Samsung Electronics Co., Ltd. | Apparatus and method for determining aggregated link costs in a mobile ad hoc network |
WO2006055273A2 (en) * | 2004-11-12 | 2006-05-26 | Meshnetworks, Inc. | A system and method to scout for routes in a wireless network |
WO2006055273A3 (en) * | 2004-11-12 | 2007-05-18 | Meshnetworks Inc | A system and method to scout for routes in a wireless network |
US7512074B2 (en) | 2004-11-12 | 2009-03-31 | Motorola, Inc. | System and method to scout for routes in a wireless network |
US20060104205A1 (en) * | 2004-11-12 | 2006-05-18 | Meshnetworks, Inc. | System and method to scout for routes in a wireless network |
US20070127379A1 (en) * | 2005-12-07 | 2007-06-07 | Hrishikesh Gossain | Method and system for improving a wireless communication route |
US8243603B2 (en) | 2005-12-07 | 2012-08-14 | Motorola Solutions, Inc. | Method and system for improving a wireless communication route |
US8199677B1 (en) * | 2005-12-14 | 2012-06-12 | Rockwell Collins, Inc. | Distance vector routing via multi-point relays |
US20080205360A1 (en) * | 2007-02-27 | 2008-08-28 | Tropos Networks, Inc. | Balancing clusters of a wireless mesh network |
US8031615B2 (en) * | 2007-02-27 | 2011-10-04 | Tropos Networks, Inc. | Balancing clusters of a wireless mesh network |
US20090168653A1 (en) * | 2007-12-31 | 2009-07-02 | St Pierre Robert P | Method and Apparatus for Mesh Routing |
US7881206B2 (en) * | 2007-12-31 | 2011-02-01 | Oracle America, Inc. | Method and apparatus for mesh routing |
US8539035B2 (en) * | 2008-09-29 | 2013-09-17 | Fujitsu Limited | Message tying processing method and apparatus |
US20100082762A1 (en) * | 2008-09-29 | 2010-04-01 | Fujitsu Limited | Message tying processing method and apparatus |
US20110085461A1 (en) * | 2009-10-14 | 2011-04-14 | Ying Liu | Flexible network measurement |
US8730819B2 (en) * | 2009-10-14 | 2014-05-20 | Cisco Teechnology, Inc. | Flexible network measurement |
US11233722B2 (en) * | 2017-12-12 | 2022-01-25 | Futurewei Technologies, Inc. | System and method for network topology management |
US20210321241A1 (en) * | 2020-04-14 | 2021-10-14 | Soter Technologies, Llc | Systems and methods for notifying particular devices based on estimated distance |
US11259167B2 (en) * | 2020-04-14 | 2022-02-22 | Soter Technologies, Llc | Systems and methods for notifying particular devices based on estimated distance |
Also Published As
Publication number | Publication date |
---|---|
US8027275B2 (en) | 2011-09-27 |
JP2003284114A (en) | 2003-10-03 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8027275B2 (en) | Route selection in a communications network using combined values of metrics of different characteristics | |
EP2541989B1 (en) | Communications system, slave node, route building method, and program | |
US7035221B2 (en) | Radio network, relay node, core node, relay transmission method used in the same and program thereof | |
US8085672B2 (en) | Wireless routing implementation | |
EP1704687B1 (en) | Cost determination in a multihop network | |
JP4433126B2 (en) | Base station selection method, mobile station and base station | |
US6973039B2 (en) | Mechanism for performing energy-based routing in wireless networks | |
US20020045453A1 (en) | Lagrange quality of service routing | |
US20080101244A1 (en) | Data routing method and apparatus | |
JP2002368789A (en) | Method and system for routing message | |
AU2003232006A1 (en) | Admission control in a mobile ad hoc network | |
CN111479305A (en) | TDMA mobile self-organizing network MAC layer routing method based on intelligent antenna | |
CN101511118B (en) | Self-organizing network route selection method based on MIMO | |
JP2001244983A (en) | Routing method and router device for radio network | |
JP4136970B2 (en) | Alternative route determination method in wireless mesh network | |
JP3928636B2 (en) | Wireless network, relay node, core node, relay transmission method used therefor, and program thereof | |
CN108307411B (en) | Mobile self-organizing network self-adaptive gateway selection method based on biological elicitation | |
US20090028058A1 (en) | Directed Mesh Network with Link Evaluation | |
CN114258105B (en) | Multi-hop data transmission method and device | |
Akbulut et al. | A Desirability Function Approach to Evaluate a Wireless Network Communication Performance | |
Zarhouni et al. | Traffic engineering and optimization routing for voip traffic in wireless mesh networks | |
CN114585044A (en) | Path selection method and router | |
CN115174466A (en) | High-reliability route optimization method for multi-mode distribution field area network control service | |
KR20200011276A (en) | Apparatus and method for routing of wireless ad-hoc network | |
Xie et al. | Implementation and evaluation of channel assignment tool for multi-radio multi-channel wireless mesh networks |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NEC CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:EBATA, KOICHI;FURUKAWA, HIROSHI;REEL/FRAME:013892/0823 Effective date: 20030319 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
LAPS | Lapse for failure to pay maintenance fees |
Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20190927 |